Re: [PATCH v3 5/6] x86/alternative: Use a single access in text_poke() where possible

From: Steven Rostedt
Date: Thu Jan 10 2019 - 13:24:16 EST


On Thu, 10 Jan 2019 10:04:28 -0800
Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote:

> > What atomicity guarantee does the above require?
>
> I was asking in the context of static calls. My understanding is that
> the write to change the imm32 of the CALL needs to be atomic from a
> code fetch perspective so that we don't jump to a junk address.
>
> Or were you saying that Intel gave an official OK on text_poke_bp()?

Yes, the latter. I was talking about Intel giving the official OK for
text_poke_bp().

-- Steve